Set this up months ago. Dude was responsive via email and seemed legit. Flash forward to today and I can't reach them. Phone disconnected, website says something about a family health issue and email is best. Problem is no one responds to email and my lowers are with them. Package signed for.

It would be a civil matter, not criminal. You don't own the items as it has not been transferred to you, but you do have what amounts to a lien on the item. The police are not going to be able to help you.

You could stop by the premises address and see if anyone is home and see about getting it transferred to another FFL.